MACROBENTHIC INVERTEBRATES IN RELATION TO SEDIMENT PROPERTIES IN SOME FISH FARMS.

National institute of Oceanography and fisheries AUKcmaterAl-Khqyria, Egypt

Abstract

Mechanical analysis, some chemical properties of sediment, composition and distribution of macrobenthic invertebrates were studied in ten fish ponds at El-Fayoum Govemorate (Egypt). The study showed that the nature of sediment ranged between sandy loam and clayey soils, while the sediment pH lied in the alkaline side. The community of benthos was represented by four groups (Annelida, Crustacea, Insecta and MoUusca).The most important factors affecting the composition and distribution of benthic community include nature of the bottom sediment, soil salinity, and its organic matter content, besides the number of rearing stocked fishes,